1. Field of the Invention
This invention relates to cartridges or cassettes of a type adapted to receive and handle an elongate strip of web material. In particular, it relates to a cartridge for containing a web of photosensitive film and for positioning in a camera equipped to expose the film to scene light. The invention contemplates use with film that is capable also of recording sound and with a camera operable to record both sound and scene light into such film.
2. Description of the Prior Art
Film cartridges of the general type shown herein include, for example, the familiar "super 8" cartridge which is adapted to contain a roll of 8mm film and to be positioned within a camera having suitable mechanism for sequentially exposing portions of the film to scene light. Cartridges of the super 8 type are described in U.S. Pat. No. 3,208,685 issued to Evan A. Edwards et al. on Sept. 28, 1965 and entitled "Anti-Friction Disc for Strip Material Cartridge" and in U.S. Pat. No. 3,208,686 issued to Evan A. Edwards et al. on Sept. 28, 1965 and entitled "Film Cartridge."
In addition, it is known to modify such super 8 cartridges to provide for sound recording on the film in the cartridge as is shown, for example, in U.S. Pat. No. 3,442,580. As disclosed therein, an intermittent film engaging mechanism advances the film frame by frame across an exposure aperture while a capstan drive arrangement advances the film past a sound recording head spaced from the exposure aperture.
A characteristic common to all of the above-mentioned cartridges, however, is that they are designed to be completely enclosed within the camera in which they are designed to be used. Because the size of the camera must be kept within reasonable limits, the above characteristic imposes a limitation on the amount of film that the cartridge can accommodate. In most instances, such a cartridge contains ample film for the user's purpose. However, in other instances, such as the filming of a particularly noteworthy event of considerable length, the film length may be inadequate and may require the user to install a fresh cartridge on one or more occasions during the filming. Under such circumstances, even though cartridge-loading cameras may be easily and swiftly reloaded, the resultant momentary interruption of filming may prove objectionable.
To provide a film cartridge capable of containing a length of film of, say, two or more times the amount contained in a cartridge of the type described above presents numerous problems. In addition to solving the problem of maintaining camera size within acceptable limits, a film transporting arrangement must be provided which is able to advance the long length of film through the cartridge while maintaining film tension forces at a relatively low level to avoid tearing the film or damaging the transporting mechanism. Additionally, if the film is of a type on which both sound and visual images may be simultaneously recorded, the film transport arrangement must also incorporate a provision for presenting the film to a suitable sound recording apparatus.